Nutrafin Basix 7 Day Fish Feeder has been specifically formulated to provide food and multi-vitamins for your aquarium fish for up to 3 days. The slow release feeder provides a varied diet of pellets and multi-vitamins for community aquariums up to 10 gallons. For larger aquariums simply add one block per 10 gallons. The Nutrafin Basix 7 Day Fish Feeder is perfect to keep your fish fed and healthy over a few days while you take that weekend getaway.